Currently, it is common for consumers to use camcorders to capture motion video images, which are viewed on a TV display, and film cameras to capture still images which are developed and optically printed to provide hardcopy prints. Carrying both types of devices is burdensome, however. Thus, there is interest in having a digital camcorder type device that captures motion images, while also allowing high quality prints to be produced from selected image frames.
Recent advances in digital camcorders include the ability to capture both motion and still images (commonly referred to as MOST cameras), and associated audio information, such as those from JVC (GR-DV1) and Sony Corp. (DCR-PC7) which allow the capture of motion video and still imagery. For example, the GR-DV1 from JVC allows a user to capture a snapshot while recording live video. Basically, the snapshot is indicated by overlaying a white border on the particular still frame of the captured live video. See U.S. Pat. No. 5,382,974, issued Jan. 17, 1995 to Soeda et al. entitled Movie Camera Having Still Picture Photographing Function and Method of Photographing Still Picture Therewith, which shows a movie camera capable of also capturing still images. Although these cameras allow one to capture motion and still images, they do not provide adequate still image quality. Furthermore, the user must decide before taking the picture whether a still or motion type image is desired. Often, the user would like to have both a motion video sequence and a still image of the same event (e.g. their daughter scoring the winning soccer goal). This is difficult to do with these prior art systems, where the user must press a special button to obtain a “still” image, rather than deciding at a later time what images they would like to have as high resolution prints.
A high definition camcorder could store a high resolution (e.g. 1280×960 pixels) motion sequence for each image frame, to provide higher quality still images. However, to produce good motion rendition of high speed objects, a high frame rate (e.g. 30 frames/sec) is required. The amount of data that would need to be processed and stored per second (e.g. 1280×960×30 pixels) would be excessive, requiring a high cost, power-hungry design having a limited recording time.
There is a need therefore for a digital motion/still camera design that reduces the processing and storage requirements, while providing both good motion rendition and the ability to obtain high resolution prints from any desired scene after it has been captured.